1. Field of the Invention
The present invention relates to a plastic container and lid and, more particularly, to a lightweight easy on and off lid with a reusable liquid seal closure.
2. Related Art
Many food and beverage products sold to the consuming public are provided in wide mouth jar-like containers. Consumers have indicated that they prefer containers which initially have a tamper-evident seal, and which can be resealed after opening for partial consumption of the contents. It is imperative that any such container have a seal which is leak-resistant from the time the lid is applied until end use by the consumer.
While seal integrity is important, the lid should allow for easy removal by the consumer. Therefore, a commercially-desirable container should have a reliable seal and a lid that is easily removed, even if the container and its contents are frozen.
Conventional containers for frozen juice concentrate have been constructed with a cardboard sidewall and metallic end lids. This construction does not provide a container that is well suited for partial consumption of its contents and re-closure. Furthermore, removal of the lid from the frozen container is not always without difficulty.
With this in mind, containers made of plastic are well suited for frozen juice concentrates, and other consumer products. Plastic containers made from an injection-molded process could be used for this purpose, since their design provides precise manufacturing control of dimensions such as heights, depths, outside and inside diameters, wall thicknesses, etc. However, injection molded plastic containers are not currently being recycled and this is a major disadvantage of such containers. Blow molding processes for making plastic containers could be utilized, since such containers are easily recyclable. However, with blow molding techniques, dimensional tolerances are more difficult to control.
A problem associated with freezable blow-molded containers is the need to accommodate slight changes in configuration due to changes in volume as the liquid freezes after the container has been sealed with a lid. The container and lid seal must remain leak-resistant not only under these conditions, but also throughout transportation and display, up to final usage by the consumer.
Current container closures, such as described in U.S. Pat. No. 4,933,133, while sealing containers effectively, have several shortcomings. Current container closures for containers such as frozen juice bottles and cans are not re-sealable. If the consumer does not wish to use all of the product at once, he must devise his own method of closing the container. Home-made solutions are generally not sturdy enough to withstand being dropped.
Another shortcoming of current container closures is that they cannot adjust to variations in the length of a flange at the open end of the container, particularly when the container is manufactured by a blow molding process. The flange forms part of the seal of the closure and the container. These variations make it more difficult for the closure to achieve and maintain a consistent seal.
Current container closures accommodate tolerances by utilizing a relatively thick walled construction to apply pressure to the sides of the container and retain contact to ensure a tight seal. However, this added weight is large enough to slow down the injection cycle time. A slow injection cycle means that fewer closure units can be manufactured at a time, reducing the ability of the manufacturer to supply units for filling. Reducing the weight of the closure has the potential, however, to degrade performance under abuse, such as when the container is dropped.
Similarly, once the tamper-evident seal is removed, current containers suffer a large reduction in their ability to withstand abuse.
U.S. Pat. Ser. No. 5,460,287 ('287), incorporated herein by reference in its entirety, of common assignee, has some advantages over the prior art. The present invention further improves upon the features of '287.